Multi-layer composite hot stamping foil and manufacturing process thereof

Abstract

The invention relates to a multi-layer composite hot stamping foil and a manufacturing process thereof. The hot stamping foil comprises a base layer, a stripping layer, a metal foil layer and a coating. The base layer is prepared from a biodegradable polyester material (such as PLA or PHA) and a nanofiber reinforcing agent, and has good mechanical strength and biodegradability. The stripping layer is made of a temperature-sensitive polyurethane material and shows a stable stripping effect at a specific temperature, and the durability is improved through UV curing. The metal foil layer is composed of silver nanoparticles and aluminum oxide, has excellent glossiness and conductivity, and is doped with magnetic particles to enhance the anti-counterfeiting function. And the outermost coating contains photocatalytic nano titanium dioxide and wear-resistant boron nitride nanoparticles, so that the self-cleaning and wear-resistant properties are achieved. Through the process steps of multi-layer co-extrusion forming, vacuum evaporation, coating, UV curing and the like, the hot stamping foil is efficient, rich in function and suitable for the fields of high-end packaging, anti-fake marks and electronic products.

Description

Technical Field

[0001] The invention relates to the processing field of hot stamping paper, and in particular to a multi-layer composite hot stamping paper and a manufacturing process thereof. Background Art

[0002] Hot stamping foil is a decorative material used to transfer metal foil to the surface of the substrate by hot pressing. It is widely used in packaging, printing, textile and other fields. Traditional hot stamping paper is generally composed of a base layer, a peeling layer, a metal foil layer and a protective coating. Each layer is transferred through a hot pressing process to make the printed matter or packaging material present a high-gloss metallic effect. Although the existing hot stamping paper has good decorative effects and performance, it still has some shortcomings in terms of environmental performance, versatility, anti-counterfeiting function and durability, which urgently need to be improved.

[0003] The manufacturing process of traditional hot stamping paper usually uses a non-environmentally friendly polyester base layer, which is difficult to degrade naturally after use, increasing the difficulty of waste disposal. In addition, the existing peeling layer usually uses thermoplastic materials, which are prone to unstable peeling at high temperatures, affecting the hot stamping effect. Although the metal foil layer can provide a good metallic luster, its thickness is usually difficult to control, and traditional metal foil materials lack further functionality, such as anti-counterfeiting properties and conductivity. Coatings are mostly used to protect the metal foil layer to prevent scratches and wear during transportation and use, but the wear resistance and functionality of existing coatings still have room for improvement.

[0004] Although the popular hot stamping paper technology in the current market can meet the decoration needs to a certain extent, with the improvement of environmental protection requirements and the widespread demand for intelligent anti-counterfeiting and functional hot stamping materials, the existing technology can no longer meet the high-end market's demand for new hot stamping paper. Therefore, the development of an environmentally friendly, more functional, multi-layer composite hot stamping paper has become a trend in the industry. In particular, there are still many technical problems to be solved in terms of enhancing the multifunctionality of hot stamping paper (such as self-cleaning, anti-counterfeiting, etc.) and improving environmental performance. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a multi-layer composite hot stamping paper and a manufacturing process thereof, which can effectively solve the deficiencies in the prior art.

[0006] The present invention is realized by the following technical scheme: a multi-layer composite hot stamping paper, comprising a base layer, the base layer is made of a biodegradable polyester material and contains a nanofiber reinforcing agent;

[0007] A peeling layer is disposed on the base layer, the peeling layer is made of a temperature-sensitive polyurethane material, and the temperature-sensitive polyurethane material exhibits different peeling properties between 50 and 80 degrees Celsius;

[0008] A metal foil layer is disposed on the peeling layer, wherein the metal foil layer is made of a composite metal nano material, including a composite layer of silver nanoparticles and aluminum oxide;

[0009] The coating is arranged on the metal foil layer, and the coating comprises photocatalytic nano titanium dioxide particles and wear-resistant reinforcing agent boron nitride nano particles.

[0010] As a preferred technical solution, the base layer is polylactic acid or polyhydroxyalkanoate, and the nanofiber reinforcement is carbon nanotubes or aramid fibers.

[0011] As a preferred technical solution, the peeling layer further includes an ultraviolet curing coating, and the coating is cured within 0.5 to 5 seconds by ultraviolet irradiation.

[0012] As a preferred technical solution, the metal foil layer has a thickness of 20 to 50 nanometers and is doped with 1 to 5 weight percent of magnetic metal particles to increase the magnetic response characteristics.

[0013] As a preferred technical solution, the particle size of the photocatalytic nano titanium dioxide particles is 10 to 50 nanometers.

[0014] As a preferred technical solution, the added amount of the wear-resistant reinforcing agent boron nitride nanoparticles is 0.5 to 3 weight percent, which is used to improve the wear resistance and scratch resistance of the hot stamping paper.

[0015] A manufacturing process of a multi-layer composite hot stamping paper of the present invention comprises the following steps:

[0016] Base preparation:

[0017] The biodegradable polyester material is mixed with the nanofiber reinforcement through a melt extrusion molding process to form the base layer, and the thickness of the base layer is controlled to be 50 to 100 microns;

[0018] Peel layer preparation:

[0019] The temperature-sensitive polyurethane is evenly coated on the surface of the base layer by coating or co-extrusion process to form a peeling layer, and the thickness of the peeling layer is controlled to be 5 to 20 microns;

[0020] Metal foil layer preparation:

[0021] Depositing composite metal nanomaterials, including silver nanoparticles and aluminum oxide, on the peeling layer by vacuum evaporation or sputtering to form a metal foil layer, wherein the thickness of the metal foil layer is controlled to be 20 to 50 nanometers;

[0022] Coating preparation:

[0023] Through the coating process, a coating containing photocatalytic nano-titanium dioxide and wear-resistant boron nitride nano-particles is evenly applied on the metal foil layer to ensure uniform distribution of the coating;

[0024] UV curing:

[0025] After the coating is formed, UV curing is performed by ultraviolet irradiation, and the curing time is controlled between 0.5 and 5 seconds to ensure the adhesion and durability of the coating.

[0026] As a preferred technical solution, the co-extrusion step includes the following details:

[0027] Raw material mixing:

[0028] Mixing polylactic acid or polyhydroxyalkanoate with nanofiber reinforcement and co-extruding using melt extrusion equipment to ensure uniform distribution of the materials;

[0029] Multi-layer extrusion:

[0030] Use multi-layer co-extrusion equipment to extrude the base layer, peeling layer and metal foil layer at one time to ensure that each layer is evenly and tightly combined.

[0031] As a preferred technical solution, the deposition of the metal foil layer is completed by the following steps:

[0032] Metal material evaporation:

[0033] Silver nanoparticles and aluminum oxide are uniformly deposited on the surface of the peeling layer by vacuum evaporation equipment to form a metal foil layer;

[0034] Thickness Control:

[0035] During the evaporation process, the thickness of the metal foil layer is controlled in real time at 20 to 50 nanometers through a precise thickness monitoring system.

[0036] As a preferred technical solution, the formation of the coating comprises the following steps:

[0037] Coating process:

[0038] Using an intelligent coating system, photocatalytic nano-titanium dioxide particles and wear-resistant boron nitride nano-particles are uniformly dispersed in a matrix and uniformly coated on a metal foil layer using a coating machine;

[0039] UV curing treatment:

[0040] UV curing equipment is used for ultraviolet curing, and the curing time is controlled between 0.5 and 5 seconds to ensure that the coating has good adhesion and wear resistance.

[0041] The beneficial effects of the present invention are as follows: the present invention adopts biodegradable polyester material as the base layer of the hot stamping paper, which can be decomposed in the natural environment, effectively reducing the pollution problem of traditional hot stamping paper to the environment, meeting the current environmental protection requirements, and is particularly suitable for application in green packaging and environmental protection industries.

[0042] The peeling layer is made of temperature-sensitive polyurethane material, which can exhibit different peeling characteristics under specific temperature conditions, making the peeling effect in the hot stamping process more stable and controllable, avoiding the incomplete or uneven peeling problem caused by temperature fluctuations in the prior art, and improving the consistency and quality of the hot stamping effect.

[0043] The metal foil layer in the present invention adopts composite metal nanomaterials, including silver nanoparticles and aluminum oxide, which not only has excellent metallic luster, but also has electrical conductivity and anti-counterfeiting properties. By doping magnetic metal particles in the metal foil layer, the hot stamping paper has a specific magnetic response function, which is suitable for anti-counterfeiting applications in high-end packaging and electronic product packaging, further expanding the application scenarios of hot stamping paper.

[0044] The coating contains photocatalytic nano-titanium dioxide particles, which give the hot stamping paper a self-cleaning function. It can effectively decompose surface stains under light and maintain the durability and cleanliness of the hot stamping effect. At the same time, the boron nitride nanoparticles in the coating can significantly improve the wear resistance of the hot stamping paper and extend its service life, especially for high-frequency contact or friction application scenarios.

[0045] Through advanced manufacturing processes such as multi-layer co-extrusion, laser etching and vacuum evaporation, the manufacturing process of the present invention is more efficient, and each layer of material is closely combined, reducing material waste and defective rate in production. In particular, the thickness control of the metal foil layer is more accurate, which improves the overall quality stability of the hot stamping paper.

[0046] The multi-layer composite hot stamping paper of the present invention not only has the decorative function of traditional hot stamping paper, but also has multifunctionality (such as anti-counterfeiting, self-cleaning, wear resistance, etc.), and is suitable for high-end packaging, anti-counterfeiting labels, electronic products and environmental protection fields. Its wide range of functions and application scenarios have brought new development opportunities to the hot stamping paper industry and has a high market value. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 It is an exploded view of the present invention. DETAILED DESCRIPTION

[0049] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0050] Any feature disclosed in this specification (including any additional claims, abstract and drawings), unless otherwise stated, may be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0051] like Figure 1 As shown, the structure of the multi-layer composite hot stamping paper of the present invention includes a base layer 1, a peeling layer 2, a metal foil layer 3 and a coating layer 4. The material and function of each layer are as follows:

[0052] The base layer is made of biodegradable polyester materials, such as polylactic acid (PLA) or polyhydroxyalkanoate (PHA). In order to enhance the mechanical strength of the base layer, a nanofiber reinforcement is added to the base layer, and the reinforcement can be carbon nanotubes or aramid fibers. The base layer not only has excellent physical properties, but also can be degraded in the natural environment, meeting environmental protection requirements. The thickness of the base layer is controlled at 50 to 100 microns, ensuring the support and toughness of the hot stamping paper.

[0053] The peeling layer is located on the base layer and is composed of a thermosensitive polyurethane material. The material exhibits good peeling properties within a temperature range of 50 to 80 degrees Celsius, enabling stable peeling during the hot pressing process to ensure the complete transfer of the metal foil layer. To further enhance the durability of the peeling layer, the peeling layer also contains a UV curing coating that can be quickly cured after 0.5 to 5 seconds of ultraviolet light exposure, ensuring the durability and long life of the hot stamping paper during the production process.

[0054] The metal foil layer is made of composite metal nanomaterials, the main components of which include silver nanoparticles and aluminum oxide. This composite metal nanomaterial not only provides excellent metallic gloss, but also has good conductivity and anti-counterfeiting functions. By doping the metal foil layer with 1 to 5 weight percent of magnetic metal particles, it has magnetic response characteristics in the hot stamping paper and can be used for anti-counterfeiting applications. The thickness of the metal foil layer is controlled between 20 and 50 nanometers to ensure that it meets the functional requirements without affecting the appearance effect.

[0055] The coating is the outermost layer of the hot stamping paper and is composed of a material containing photocatalytic nano-titanium dioxide particles and wear-resistant boron nitride nano-particles. The photocatalytic nano-titanium dioxide particles have a particle size of 10 to 50 nanometers and can produce a photocatalytic reaction under light, which keeps the coating surface self-cleaning and prevents stains from accumulating. The wear-resistant boron nitride nano-particles can significantly improve the wear resistance of the hot stamping paper and prevent scratches and abrasions in daily use. The coating is cured by a UV curing process with a curing time of 0.5 to 5 seconds, ensuring uniform adhesion and long-term durability of the coating.

[0056] The multi-layer composite hot stamping paper of the present invention is prepared by the following steps, and the specific steps are as follows:

[0057] First, a biodegradable polyester material (such as PLA or PHA) is uniformly mixed with a nanofiber reinforcement (such as carbon nanotubes or aramid fibers). The mixture is extruded using a melt extrusion device to obtain a base material. The thickness of the base is controlled between 50 and 100 microns to ensure that it has good support and flexibility.

[0058] A thermosensitive polyurethane material is coated on the base layer to form a peeling layer. The coating process can be carried out by a coating device, and the thickness of the peeling layer is controlled between 5 and 20 microns. Subsequently, the peeling layer is UV cured, and the UV irradiation time is 0.5 to 5 seconds to ensure the curing speed and adhesion of the peeling layer.

[0059] The composite metal nanomaterial (silver nanoparticles and aluminum oxide) is uniformly deposited on the surface of the peeling layer by vacuum evaporation or sputtering process to form a metal foil layer. The thickness of the metal foil layer is controlled between 20 and 50 nanometers. In order to enhance the functionality of the metal foil layer, 1 to 5 weight percent of magnetic metal particles can be added during the evaporation process to give it magnetic response characteristics.

[0060] The outermost coating is formed by a coating process. The coating material containing photocatalytic nano titanium dioxide particles and wear-resistant boron nitride nanoparticles is evenly coated on the metal foil layer using intelligent coating equipment. In order to ensure the adhesion and durability of the coating, the coating is then UV cured for 0.5 to 5 seconds. The cured coating surface is smooth and uniform, with self-cleaning function and strong wear resistance.

[0061] The above-mentioned layers of materials are compounded in sequence through a multi-layer co-extrusion molding process to finally obtain the multi-layer composite gold foil paper of the present invention. In order to ensure the uniformity of the thickness of each layer and the close bonding between the layers, the entire manufacturing process is carried out under strict temperature and pressure control.

[0062] During the manufacturing process of hot stamping paper, thickness monitoring equipment is used to monitor the thickness of each layer in real time to ensure that the thickness of each layer meets the design requirements. In addition, physical performance tests are also required for finished products during the production process, including peel strength, abrasion resistance, self-cleaning, etc., to ensure the stability and consistency of product quality.

[0063] Example 1: Preparation of environmentally friendly multi-layer composite hot stamping paper

[0064] Base preparation:

[0065] The base material is polylactic acid (PLA), which is biodegradable and has environmental advantages. In order to enhance its mechanical properties, 3% carbon nanotubes are added to PLA as a reinforcing agent. The mixing of PLA and carbon nanotubes is carried out by a twin-screw extruder, and the extrusion temperature is controlled at 190°C. After melt extrusion, a base layer with a thickness of 80 microns is formed.

[0066] The base layer has excellent mechanical strength and flexibility, as well as good biodegradability, meeting environmental protection requirements.

[0067] Peel layer preparation:

[0068] A layer of temperature-sensitive polyurethane (PU) material with a thickness of 10 microns is evenly coated on the base layer. The PU material exhibits good peeling properties at 55°C and is suitable for hot pressing processes.

[0069] After coating, the peeling layer is cured by UV curing equipment, and the UV irradiation time is controlled within 2 seconds to ensure that the peeling layer has excellent stability and peeling performance.

[0070] Metal foil layer preparation:

[0071] The composite metal nanomaterial is deposited on the peeling layer through vacuum evaporation process. The main components are silver nanoparticles (particle size 20 nanometers) and aluminum oxide (particle size 30 nanometers). The thickness of the metal foil layer is 30 nanometers. This layer not only has high gloss, but also has certain conductive properties.

[0072] 2% ferrite magnetic particles are added to the metal foil layer to make it magnetically responsive for high-end anti-counterfeiting applications.

[0073] Coating preparation:

[0074] The outermost coating is composed of photocatalytic nano titanium dioxide particles (particle size 15 nanometers) and wear-resistant boron nitride particles (particle size 10 nanometers), which are evenly coated on the surface of the metal foil layer through a coating device, and the coating thickness is 5 microns.

[0075] The coating is irradiated for 2 seconds in a UV curing device to ensure uniform curing and self-cleaning properties and high wear resistance.

[0076] Performance Test:

[0077] The multi-layer composite hot stamping paper has been tested in practice and has shown excellent peeling effect, high gloss and good self-cleaning performance, and has passed the abrasion resistance test, making it suitable for high-end packaging fields.

[0078] Example 2: Preparation of functional multi-layer composite hot stamping paper

[0079] Base preparation:

[0080] The base layer uses polyhydroxyalkanoate (PHA) as the main material, which is also biodegradable. In order to improve the toughness of the base layer, 2% of aramid fiber is added to PHA, and extrusion molding is carried out using a single screw extruder, and the extrusion temperature is controlled at 180°C. The thickness of the base layer after molding is 70 microns, with high tensile strength and flexibility.

[0081] Peel layer preparation:

[0082] A layer of temperature-sensitive polyurethane (PU) with a thickness of 15 microns is coated on the surface of the base layer by a coater. The PU material has good peeling properties at 60°C and can stably release the metal foil layer during the hot stamping process.

[0083] The peeling layer is irradiated by UV curing equipment, and the curing time is controlled within 3 seconds to ensure that the peeling layer is stable and durable during the hot stamping process.

[0084] Metal foil layer preparation:

[0085] The metal foil layer is deposited on the peeling layer by a sputtering process and consists of silver nanoparticles (particle size 15 nanometers) and copper nanoparticles (particle size 25 nanometers). The thickness of the foil layer is 25 nanometers. This layer has high gloss and good conductivity, and is suitable for anti-counterfeiting labeling applications for electronic products.

[0086] At the same time, 1% magnetic iron oxide particles are added to the metal foil layer to further enhance the anti-counterfeiting function of the hot stamping paper.

[0087] Coating preparation:

[0088] Photocatalytic nano-titanium dioxide particles (20 nanometers in diameter) and nano-silicon carbide particles (12 nanometers in diameter) are added to the coating material and evenly coated on the surface of the metal foil layer through a coating device with a coating thickness of 6 microns. The coating not only has a self-cleaning function, but also provides anti-ultraviolet protection.

[0089] The coating is irradiated with UV for 4 seconds in a UV curing device to ensure that the coating has sufficient adhesion and durability.

[0090] Performance Test:

[0091] This multi-layer composite hot stamping paper showed excellent conductivity, self-cleaning ability and wear resistance in functional tests, and has good anti-counterfeiting properties. It is particularly suitable for anti-counterfeiting labels and electronic product packaging fields with high security requirements.

[0092] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that are not conceived through creative work should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope defined in the claims.

Claims

1. A multi-layer composite hot stamping paper, characterized in that: include: A base layer, wherein the base layer is made of a biodegradable polyester material and contains a nanofiber reinforcement; A peeling layer is disposed on the base layer, the peeling layer is made of a temperature-sensitive polyurethane material, and the temperature-sensitive polyurethane material exhibits different peeling properties between 50 and 80 degrees Celsius; A metal foil layer is disposed on the peeling layer, wherein the metal foil layer is made of a composite metal nano material, including a composite layer of silver nanoparticles and aluminum oxide; The coating is arranged on the metal foil layer, and the coating comprises photocatalytic nano titanium dioxide particles and wear-resistant reinforcing agent boron nitride nano particles.

2. The multi-layer composite hot stamping paper according to claim 1, characterized in that: The base layer is polylactic acid or polyhydroxyalkanoate, and the nanofiber reinforcement is carbon nanotube or aramid fiber.

3. The multi-layer composite hot stamping paper according to claim 1, characterized in that: The release layer further includes an ultraviolet curing coating, which is cured within 0.5 to 5 seconds by ultraviolet irradiation.

4. The multi-layer composite hot stamping paper according to claim 1, characterized in that: The metal foil layer has a thickness of 20 to 50 nanometers and is doped with 1 to 5 weight percent of magnetic metal particles to increase magnetic response characteristics.

5. The multi-layer composite hot stamping paper according to claim 1, characterized in that: The particle size of the photocatalytic nano titanium dioxide particles is 10 to 50 nanometers.

6. The multi-layer composite hot stamping paper according to claim 1, characterized in that: The added amount of the wear-resistant reinforcing agent boron nitride nanoparticles is 0.5 to 3 weight percent, and is used to improve the wear resistance and scratch resistance of the hot stamping paper.

7. A manufacturing process for multi-layer composite hot stamping paper, characterized in that: The following steps are involved: Base preparation: The biodegradable polyester material is mixed with the nanofiber reinforcement through a melt extrusion molding process to form the base layer, and the thickness of the base layer is controlled to be 50 to 100 microns; Peel layer preparation: The temperature-sensitive polyurethane is evenly coated on the surface of the base layer by coating or co-extrusion process to form a peeling layer, and the thickness of the peeling layer is controlled to be 5 to 20 microns; Metal foil layer preparation: Depositing composite metal nanomaterials, including silver nanoparticles and aluminum oxide, on the peeling layer by vacuum evaporation or sputtering to form a metal foil layer, wherein the thickness of the metal foil layer is controlled to be 20 to 50 nanometers; Coating preparation: Through the coating process, a coating containing photocatalytic nano-titanium dioxide and wear-resistant boron nitride nano-particles is evenly applied on the metal foil layer to ensure uniform distribution of the coating; UV curing: After the coating is formed, UV curing is performed by ultraviolet irradiation, and the curing time is controlled between 0.5 and 5 seconds to ensure the adhesion and durability of the coating.

8. The manufacturing process of the multi-layer composite hot stamping paper according to claim 7, characterized in that: The co-extrusion step includes the following details: Raw material mixing: Mixing polylactic acid or polyhydroxyalkanoate with nanofiber reinforcement and co-extruding using melt extrusion equipment to ensure uniform distribution of the materials; Multi-layer extrusion: Use multi-layer co-extrusion equipment to extrude the base layer, peeling layer and metal foil layer at one time to ensure that each layer is evenly and tightly combined.

9. The manufacturing process of the multi-layer composite hot stamping paper according to claim 7, characterized in that: The deposition of the metal foil layer is accomplished by the following steps: Metal material evaporation: Silver nanoparticles and aluminum oxide are uniformly deposited on the surface of the peeling layer by vacuum evaporation equipment to form a metal foil layer; Thickness Control: During the evaporation process, the thickness of the metal foil layer is controlled in real time at 20 to 50 nanometers through a precise thickness monitoring system.

10. The manufacturing process of the multi-layer composite hot stamping paper according to claim 7, characterized in that: The formation of the coating comprises the following steps: Coating process: Using an intelligent coating system, photocatalytic nano-titanium dioxide particles and wear-resistant boron nitride nano-particles are uniformly dispersed in a matrix and uniformly coated on a metal foil layer using a coating machine; UV curing treatment: UV curing equipment is used for ultraviolet curing, and the curing time is controlled between 0.5 and 5 seconds to ensure that the coating has good adhesion and wear resistance.

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